Pressure-equalizing addition funnel

Fig. 85 Separatory funnels in triplicate, (a) Plain, (b) Compromise separatory addition funnel, (c) Pressure-equalizing addition funnel.

A 50 mL addition funnel with pressure-equalization arm Several flash-chromatography columns Rotary evaporator... 

A 500 mL, three-necked, round-bottomed flask was equipped with a magnetic stirring bar, thermometer, reflux condenser, and an additional, pressure-equalizing funnel capped... 

Coupling Reaction. Exactly 31.4g of tributyltinchloride is weighed out directly in a 100ml 3-necked flask. The flask is then equipped with a Y adaptor, a precision bore Teflon paddle stirrer, an additional funnel (with pressure equalizing arm), thermometer, and a reflux condenser having a nitrogen inlet. 

In figure 4 is shown how a separatory funnel and a pressure equalized addition funnel are made. The funnel part is just a PP funnel from the grocery store and what it is attached to is a stainless steel ball valve. See how the addition funnel is made by using a rubber stopper and an extra extension of tubing to the top of the funnel Well, that s how one can make a sealed addition funnel out of the ordinary glass separatory funnel that one gets with a distillation kit or from wherever. 

Setup your glassware for simple distillation with a claisen adapter, three way adapter, pressure-equalized addition funnel, water cooled condenser, vacuum adapter and receiver flask to catch any condensed solvent vapors. 

Methyl-2-propen-l-ol, purchased from Aldrich Chemical Company, was distilled from anhydrous potassium carbonate. It was added directly to the n-butyllithium solution using a long needle. The checkers quickly replaced the pressure-equalizing dropping funnel with a serum cap to carry out this addition. The funnel was fitted to a small dry flask to prevent the introduction of moisture during the addition period and replaced on the reaction flask immediately afterwards. 

Tetrahydrofuran, anhydrous, 99.9t (water content <0.006t) was purchased from Aldrich Chemical Company, Inc., and used as received. The vinyl bromide solution was prepared In a 500-mL, round-bottomed flask fitted with a glass stopper. The stoppered flask containing the tetrahydrofuran was chilled to about 5 C and weighed. The vinyl bromide, also chilled to about 5°C, was rapidly poured Into the tetrahydrofuran until the desired amount had been added. The flask was stoppered, the contents mixed by shaking, allowed to warm to about 16°C, and then added to the pressure-equalizing addition funnel. 

In a three-necked flask fitted with a thermometer, a stirrer, a condenser (drying tube), and a pressure-equalizing addition funnel, HMPT (25 ml, 0.14 mole) and anhydrous ether (30 ml) are introduced. Finely divided lithium (1.75 g, 0.25 g-atom) is then added... 

A 500-ml, three-necked, round-bottom flask is fitted with a mechanical stirrer, a pressure-equalizing addition funnel and a reflux condenser (drying tube). The flask is charged with 100 ml of dry dimethylformamide, 9.2 ml (0.1 mole) of dry -butyl alcohol, and 28 g (0.107 mole) of dry triphenylphosphine. The flask is cooled in a water bath, stirring is begun, and bromine (approx. 16 g, 0.1 mole) is added over about 15 minutes. 

In a 250-ml three-necked flask fitted with a magnetic stirrer, a pressure-equalizing dropping funnel, and a thermometer is placed a solution of l,4-cyclohexanediol(l 1.4g, 0.10 mole), 35 ml of chloroform, and 27 ml of dry pyridine. The solution is cooled in an ice bath to 0-5 and is maintained below 5 throughout the addition. A solution of benzoyl chloride (14 g, 0.10 mole) in 30 ml of dry chloroform is added with stirring at a rate so as to keep the temperature below 5° (approx. 40 minutes). After completion of the addition, the mixture is allowed to come to room temperature and stand overnight. The chloroform solution is washed four times with 50-mI portions of water, once with 50 ml of 5 % sulfuric acid solution, and finally with saturated sodium chloride solution. The chloroform solution is then dried (sodium sulfate), and the solvent is removed. Fractionation of the residue gives a cis and trans mixture of 4-benzoyloxycyclohexanol, bp 175-17870.2 mm, as a very viscous oil, yield about 55%. 

The reaction is carried out under argon in a 2-liter three-necked flask fitted with a mechanical stirrer, reflux condenser, 250-ml pressure-equalizing addition funnel, and gas inlet and outlet. After purging with argon, the flask is charged with a solution of 89 g (0.48 mole) of ferrocene in 1 liter of dry tetrahydrofuran. The solution is next heated to 45°, and there is added dropwise with stirring, 155 ml (0.29 mole) of an -butyllithium solution (15% in heptane-pentane, 2 1, Foote Mineral Co.) during a period of 75 minutes. The resultant solution is maintained at 45° for an additional 2 hours, then is cooled to —77° by means of an external Dry Ice-chloroform bath. 

A dry 5(X)-mI flask equipped with a thermometer, pressure-equalizing dropping funnel, and magnetic stirrer is flushed with nitrogen and then maintained under a static pressure of the gas. The flask is charged with 50 ml of tetrahydrofuran and 13.3 ml (0.15 mole) of cyclopentene, and then is cooled in an ice bath. Conversion to tricyclo-pentylborane is achieved by dropwise addition of 25 ml of a 1 M solution of diborane (0.15 mole of hydride see Chapter 4, Section 1 for preparation) in tetrahydrofuran. The solution is stirred for 1 hour at 25° and again cooled in an ice bath, and 25 ml of dry t-butyl alcohol is added, followed by 5.5 ml (0.05 mole) of ethyl bromoacetate. Potassium t-butoxide in /-butyl alcohol (50 ml of a 1 M solution) is added over a period of 10 minutes. There is an immediate precipitation of potassium bromide. The reaction mixture is filtered from the potassium bromide and distilled. Ethyl cyclopentylacetate, bp 101730 mm, 1.4398, is obtained in about 75% yield. Similarly, the reaction can be applied to a variety of olefins including 2-butene, cyclohexene, and norbornene. 

In a 2-1. three-necked flask fitted with an efficient reflux condenser, stirrer, and pressure-equalizing dropping funnel are placed 216 g. (2.0 moles) of anisole (Note 1) and 400 ml. of methylene chloride (Note 2). The reflux condenser is attached to a drying tower. The solution is brought to reflux temperature with a heating mantle, and 167 ml. (278 g., 2.06 moles) of sul-furyl chloride (Note 3) is added dropwise over a 3-hour period. When the addition is complete, heating is continued for an additional 15 hours (Note 4). 

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